Rear bumper for an automobile



FIG. 1 is a front elevation view of a rear bumper for an automobile showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevation view thereof, the left side elevation view is a mirror image of the right side elevation view; and,

FIG. 4 is a perspective view thereof.

The broken lines in the drawings are illustrative purposes only and form no part of the claimed design. 

What is claimed is; the ornamental design for, a rear bumper for an automobile, as shown and described. 